ISO 9141 Communication Link

The ISO 9141 communication link:
^ consists of a single wire, Circuit 70 (LB/W).
^ provides a common link for communication to an off-board tester through the data link connector (DLC) located under the instrument panel to the right of the steering column.
^ does not allow module-to-module communications.

The micro-processor based subsystems included on this network are:
^ anti-lock brakes
^ supplemental air bag system
^ keyless entry
^ perimeter anti-theft
^ power locks and windows
^ interior lighting control
^ warning indicator control

Fault Tolerance
The ISO 9141 communication link will fail if any of the following occur:
^ Circuit 70 (LB/W) shorted to ground.
^ Circuit 70 (LB/W) shorted to battery positive voltage (B+).
^ the module loses power or ground supply.
^ a module failure shorts the communication network internally.

Purpose
The information within this section is designed to diagnose ISO 9141 communication link concerns.

These concerns may:
^ affect normal functional operations of the vehicle.
^ be directly related to customer concerns.
^ be undetectable except during diagnostics.

Module Identification
Modules included on this ISO 9141 communication link include:

Air Bag Diagnostic Monitor
^ located behind the right cowl trim panel.
^ a failed air bag diagnostic monitor may cause no communication condition on diagnostic communication network.

Anti-Lock Brake System (ABS) Module
^ located under the battery tray in the lower left of the engine compartment.
^ a failed anti-lock brake module may cause no communication condition on diagnostic communication network.

Driver Door Module
^ located inside driver door behind front door trim panel.

Driver Seat Module
^ located under the driver seat.

Lighting Control Module
^ located behind the instrument panel to the right of the steering column.